摘要:
A system for regulating the transfer impedance of a plurality of current-to-voltage converters to a substantially equal value includes a reference voltage source and a reference impedance for providing a reference current. A reference current-to-voltage converter is responsive to the reference current and provides an output voltage. A comparator is responsive to the reference voltage and the output voltage and provides a control signal to the reference current-to-voltage converter and to all the other current-to-voltage converters to maintain the transfer impedance of all the current-to-voltage converters constant.
摘要:
In a controllable amplifier circuit with an amplifier transistor a further transistor is provided that, when actuated under control conditions, deprives the amplifier transistor of at least a part of the input signal.
摘要:
A signal input circuit composed of a control member, such as a PIN diode, for controllable attenuation of an input signal, and reactances for selection of the input signal, wherein the signal frequency current is regulated by the control member such that the operating power required by the input circuit remains constant to the greatest possible degree in spite of the regulation.
摘要:
In a circuit producing an output voltage independent of temperature and comprising first and second pairs of interconnected transistors arranged in parallel circuit branches, the active transistor areas of the transistors within each pair are arranged to be different.
摘要:
An amplifier stage for use with low-resistance AC voltage sources has first and second complimentary transistors, each having a control terminal, a current input terminal and a current output terminal. The transistors are connected together at a first junction point, a current terminal of the second complementary transistor being connected at the first junction point to a corresponding current terminal of the first complimentary transistor. The respective other corresponding current terminals of the transistors are connected to respective opposite poles of a direct current supply, so that the first transistor, the second transistor, and the direct current supply form a series connection providing a common quiescent current to the transistors. The transistors are each provided with a respective separate direct current operating voltage at a respective control terminal. The transistors are connected to receive an input AC voltage at respective corresponding current input terminals, thereby receiving the input AC voltage in parallel.
摘要:
A signal input circuit comprising a control member for the controllable attenuation of the input signal and firmly set reactances for the selection of the input signal, wherein the reactances are connected and dimensioned in such a way that there exists a circuit point which has a large impedance compared to the impedance of the signal source, and the control member acts upon this circuit point.
摘要:
A remote control circuit which operates on a frequency basis and essentially with analog signals. The remote control circuit includes at the transmitting end a controlled oscillator, a frequency/direct signal converter and a comparator connected together into a frequency control loop. A transmitter is also provided which is fed by the oscillator of the control loop. A control path including a frequency signal source and a frequency/direct signal converter is provided at the transmitting end and receives its input signal from the frequency signal source. The converter of the control path is connected with the one input of the comparator of the control circuit. At the receiving end there is provided an amplifier, a frequency/direct signal converter and an evaluation circuit.
摘要:
In a radio receiver in accordance with the heterodyne principle or with the homodyne principle, two additional transmission channels are provided for interference suppression. The two additional transmission channels have a different degree of distortion. Either mixing with a heterodyne oscillator signal takes place in each of the two transmission channels and the resultant intermediate frequency signals or baseband signals are added in phase opposition to give a sum signal, or the output signals of the two additional transmission channels are added in phase opposition to give a sum signal and the resultant sum signal is mixed with a heterodyne oscillator signal to give an intermediate frequency signal or baseband signal. The signals obtained after addition and mixing and derived from the output signals of the two additional transmission channels are frequency-selected and demodulated, and the demodulated signal is used for gain control.
摘要:
In an integrated circuit arrangement with a protective arrangement at least partially integrated into it and protecting the integrated circuit arrangement from high-energy electrical faults, the protective arrangement has an ohmic resistance in the form of one or more resistance areas that is designed so as to absorb a major proportion of the energy from electrical faults in the event of limit loads and distribute the heat generated within it by the energy absorption over a surface of the protective arrangement such that the protective arrangement affected by the heat energy of the ohmic resistance is not thermally overloaded. Furthermore, the protective arrangement has a voltage-limiting element or several voltage-limiting elements to limit the interference voltage.
摘要:
In a radio receiver in which the received signal is converted by mixing into an intermediate frequency signal and/or a baseband signal, and in which an apparatus is provided which generates an intermediate frequency signal and/or baseband signal and derives therefrom a control signal for suppression or reduction of interfering disturbances, the signal fed to the apparatus is distorted in the apparatus in such a way that the signal distortion effected in the apparatus is greater than the distortion to which the signal fed to the receiver is subjected in the receiving section of the receiver.